In this description ‘a movement of a ship’ refers to a translative movement along an axis or a rotational movement about an axis. In particular, the movement in question will generally be selected from:                A translative movement of the ship along a longitudinal axis (also known as ‘surge’),        A translative movement of the ship along a transverse axis (also known as ‘sway’),        A translative movement of the ship along a vertical axis (also known as ‘heave’),        A rotational movement of the ship about the longitudinal axis (also known as ‘rolling’),        A rotational movement of the ship about the transverse axis (also known as ‘pitch’),        A rotational movement of the ship about the vertical axis (also known as ‘yaw’),        
Certain operations carried out by the ship or from the ship, e.g., deployment or recovery of a drone, require the ship to be highly stable. Swells generally cause the ship to execute at least one of the following movements.
In order to safely carry out an operation requiring the ship to be stable, the movements of the ship under the effects of the swell must be predicted in order to anticipate them with suitable movements for the execution of the operation and/or to compensate the movements induced by the swell.
To this end, various methods for predicting at least one movement of a ship under the effect of a swell are already known from the prior art. However, such prior-art methods generally do not allow for the movements of the ship under the effects of the swell to be anticipated sufficiently in advance or sufficiently accurately, or are very complex to implement.